Re: [Qemu-devel] [PATCH] linux-user: fix getrusage and wait4 failures with invalid rusage struct

[Andreas Färber]

Am 08.04.2014 19:24, schrieb Petar Jovanovic:
> From: Petar Jovanovic <address@hidden>
> 
> Implementations of system calls getrusage and wait4 have not previously
> handled correctly cases when incorrect address of struct rusage is
> passed.
> This change makes sure return values are correctly set for these cases.
> 
> Signed-off-by: Petar Jovanovic <address@hidden>
> ---
>  linux-user/syscall.c |   11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 9864813..fc52f0b 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -6309,7 +6309,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>              struct rusage rusage;
>              ret = get_errno(getrusage(arg1, &rusage));
>              if (!is_error(ret)) {
> -                host_to_target_rusage(arg2, &rusage);
> +                ret = host_to_target_rusage(arg2, &rusage);
>              }
>          }
>          break;

Why do you always set ret here ...

> @@ -6974,6 +6974,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>              abi_long status_ptr = arg2;
>              struct rusage rusage, *rusage_ptr;
>              abi_ulong target_rusage = arg4;
> +            abi_long rusage_err;
>              if (target_rusage)
>                  rusage_ptr = &rusage;
>              else
> @@ -6985,8 +6986,12 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
> arg1,
>                      if (put_user_s32(status, status_ptr))
>                          goto efault;
>                  }
> -                if (target_rusage)
> -                    host_to_target_rusage(target_rusage, &rusage);
> +                if (target_rusage) {
> +                    rusage_err = host_to_target_rusage(target_rusage, 
> &rusage);
> +                    if (rusage_err) {
> +                        ret = rusage_err;
> +                    }
> +                }
>              }
>          }
>          break;

... but only on error here? Isn't obvious from the commit message.

Regards,
Andreas

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